PTSD Can Be Predicted By Pre-Deployment Hormone Levels, Texas Researchers Say

AUSTIN, TX — New scientific findings by University of Texas at Austin neuroscience researchers suggest that the likelihood of a soldier to develop post-traumatic stress disorder (PTSD) can be predicted by hormone levels prior to deployment.

Up to 20 percent of U.S. veterans who served in Iraq and Afghanistan developed symptoms of PTSD from wartime trauma. The new research indicates some soldiers might have a hormonal predisposition to experience such stress-related disorders.

The findings center on the stress hormone cortisol, which is released as part of the body’s flight-or-fight response to life-threatening emergencies. Seminal research from the 1980s connected abnormal cortisol levels to an increased risk for PTSD, university officials noted. But three decades of subsequent research have produced a mixed bag of findings, "dampening enthusiasm for the role of cortisol as a primary cause of PTSD," scientists said.

Now, new findings published in the journal Psychoneuroendocrinology point to cortisol’s critical role in the emergence of PTSD, but only when levels of testosterone — one of most important of the male sex hormones — are suppressed, researchers said.

“Recent evidence points to testosterone’s suppression of cortisol activity, and vice versa," said UT Austin professor of psychology Robert Josephs, the first author of the study. "It is becoming clear to many researchers that you can’t understand the effects of one without simultaneously monitoring the activity of the other."

Josephs suggests that past scientific efforts to link PTSD to cortisol may have failed in not taking into account the powerful effect testosterone has on the hormonal regulation of stress.

To achieve the findings, UT Austin researchers used hormone data obtained from saliva samples of 120 U.S. soldiers before deployment and tracked their monthly combat experiences in Iraq to examine the effects of traumatic war-zone stressors and PTSD symptoms over time, according to university officials.

Before deployment, soldiers’ stress responses were tested in a stressful CO2 inhalation challenge, Josephs said: “Healthy stress responses showed a strong cortisol increase in response to the stressor, whereas abnormal stress responses showed a blunted, nonresponsive change in cortisol.”

The upshot: Soldiers who had an abnormal cortisol response to the CO2 inhalation challenge were more likely to develop PTSD from war-zone stress, scientists concluded. Conversely, soldiers who had an elevated testosterone response to the CO2 inhalation challenge were not likely to develop PTSD, regardless of the soldiers’ cortisol response, according to scientists.

“The means through which hormones contribute to the development of PTSD and other forms of stress-related mental illness are complex,” said Adam Cobb, a UT Austin clinical psychology doctoral candidate and co-author of the study. “Advancement in this area must involve examining how hormones function together, and with other psychobiological systems, in response to ever-changing environmental demands.”

The finding could aid in determining the effectiveness of preventative interventions targeting those with at-risk profiles of hormone stress reactivity, scientists said.

“We are still analyzing more data from this project, which we hope will reveal additional insights into risk for combat-related stress disorders and ultimately how to prevent them,” said Michael Telch, clinical psychology professor and corresponding author of the study.
The new findings add to a series of published reports from the Texas Combat PTSD Risk Project, a study funded by the Defense Advanced Research Projects Agency aimed at identifying biological, psychological and environmental vulnerability factors that predict the emergence of PTSD and other psychological problems among soldiers deployed to Iraq, university officials said.

>>> Image provided by University of Texas at Austin